A Novel Application of Serum Creatinine and Cystatin C to Predict Sarcopenia in Advanced CKD

Abstract

Sarcopenia is highly prevalent in patients with advanced chronic kidney disease (CKD), yet a reliable serum index has not been established. The product of serum creatinine and the estimated glomerular filtration rate based on cystatin C (Cr×eGFRcys) was recently proposed as a sarcopenia index (SI), approximately to 24-h filtered creatinine through the glomerulus. We aimed to evaluate the diagnostic validity of the novel SI in advanced CKD. In 297 patients with non-dialysis stage 3b-5 CKD, aged 68.8 ± 12.9 years, the total skeletal muscle mass (SMM), handgrip strength (HGS), and usual gait speed were assessed. Sarcopenia was defined based on the Asian Working Group for Sarcopenia 2019 consensus update. The prevalence of sarcopenia in this cohort was 20.2%. The SI correlated moderately with SMM (r = 0.503, P < 0.001), HGS (r = 0.508, P < 0.001), and gait speed (r = 0.381, P < 0.001); the independency of the SI with three muscle metrics was confirmed after extensive adjustment. For sarcopenia prediction, the SI had acceptable discriminative powers in males [area under the receiver operating characteristic curve (AUC) 0.646, 95% confidence interval (CI) 0.569–0.718] and females (AUC 0.754, 95% CI 0.670–0.826). In males, the best cut-off was 53.9, which provided 71.1% sensitivity, 58.0% specificity, 32.9% positive predictive value (PPV), and 87.4% negative predictive value (NPV); in females, the best cut-off was 45.8, which provided 81.8% sensitivity, 62.3% specificity, 31.0% PPV, and 94.3% NPV. In conclusion, Cr×eGFRcys could be served as a surrogate marker for sarcopenia and may be helpful for sarcopenia screening in advanced CKD. Further studies are needed to expand our investigation.

A New Index Based on Serum Creatinine and Cystatin C Can Predict the Risks of Sarcopenia, Falls and Fractures in Old Patients with Low Bone Mineral Density

“…The association between SI and physical performance was rarely evaluated in previous studies. SI was reported to be positively correlated with gait speed [ 12 ], and our study found SI to be negatively correlated with FCST. This suggests that SI is significantly associated with physical performance, not just muscle mass and strength.…”

“…Due to the properties of free glomerular filtration and renal tubular reabsorption, timed urinary creatinine excretion is a reliable marker for predicting muscle mass [ 11 ]. Additionally, a surrogate for 24 h filtered creatinine has been proposed, which is calculated as the product of serum creatinine and glomerular filtration rate [ 12 ].…”

Serum creatinine/cystatin C ratio as a muscle mass evaluating tool and prognostic indicator for hospitalized patients: A meta-analysis

“…Twelve articles presented the AUC value for CCR in the diagnosis of sarcopenia ( 7 , 21 , 24 , 34 , 40 – 42 , 45 – 47 , 49 , 50 ). Among them, two studies only reported AUC values [male/female: 0.813/0.613 ( 50 ); 0.752/0.754 ( 24 )], and the other 10 provided the mean AUC and SE values.…”

“…There were 13 studies with 5,771 patients evaluated the correlation between CCR and HGS ( 6 , 7 , 21 , 22 , 24 , 34 – 36 , 41 , 42 , 46 , 47 , 49 ). There were positive and significant correlations between CCR and all the CTASM types (Fisher’s Z = 0.39; 95% CI, 0.32–0.45; I 2 = 82%; P < 0.001) ( Figure 4 ).…”

Sarcopenia and sarcopenic obesity in chronic kidney disease: update on prevalence, outcomes, risk factors and nutrition treatment

“…Methods to assess muscle quantity and composition are being tested for validity, reliability and accuracy, and may play a relevant role in the future [1]. Serum creatinine and creatinine index can be used to estimate muscle mass under steady-state conditions in both NDD-CKD and haemodialysis [27] and can be used as a surrogate marker for sarcopenia in these patients [28][29][30][31]. However, the precise creatinine index value to identify patients with low muscle mass or sarcopenia is not clear [27].…”